The invention resides in a heat exchanger for a water-cooled internal combustion engine with lubricant cooling and external exhaust gas recirculation.
In order to comply with emission requirements, exhaust gas is frequently recirculated to the fresh air/fuel mixture- or, respectively, the intake air flow of the engine in order to lower the combustion temperature and, as a result, the NO.sub.x content of the exhaust gas. The NO.sub.x content can be further reduced if the recirculated exhaust gas is cooled. However, such cooling poses some problems as it requires a corresponding cooler which has to be accommodated in the engine compartment where there is little space in today's motor vehicles especially if a lubricant cooler is already present as it is often the case in connection with powerful internal combustion engine.